# -*- coding: utf-8 -*-
#
# This file is part of PyGaze - the open-source toolbox for eye tracking
#
#    PyGaze is a Python module for easily creating gaze contingent experiments
#    or other software (as well as non-gaze contingent experiments/software)
#    Copyright (C) 2012-2013  Edwin S. Dalmaijer
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>

from pygaze import settings
if settings.DISPTYPE == "psychopy":
    try:
        from psychopy.visual import Aperture
    except:
        raise Exception("Error in plugins.frl: PsychoPy could not be loaded!")

else:
    try:
        import pygame
    except:
        raise Exception("Error in plugins.frl: PyGame could not be loaded!")

import pygaze
from pygaze._misc.misc import pos2psychopos, psychopos2pos


class FRL:
    
    """Gaze contingent FRL"""
    
    def __init__(self, disptype=settings.DISPTYPE, pos="centre", dist=125, \
        size=200):

        """Initializes FRL object
        
        arguments
        None
        
        keyword arguments
        disptype    --    display type, either "psychopy" or "pygame"
                    (default = DISPTYPE)
        pos        --    a string indicating the FRL position in relation to
                    gaze position; allowed are "centre", "top",
                    "topright", "right", "bottomright", "bottom",
                    "bottomleft", "left", "topleft" (default =
                    "centre")
        dist        --    distance between gaze position and FRL center in
                    pixels (default = 125)
        size        --    FRL diameter in pixels (default = 200)
        """

        # FRL characteristics
        self.pos = pos
        self.dist = dist
        self.size = size

        # FRL distance
        # horizontal distance between gaze position and FRL-centre
        self.frlxdis = ((self.dist**2)/2)**0.5
        # vertical distance between gaze position and FRL-centre
        self.frlydis = ((self.dist**2)/2)**0.5
        # FRL position
        if pos in ["center","centre"]:
            self.frlcor = (0, 0)
        elif pos == "top":
            self.frlcor = (0, -self.dist)
        elif pos == "topright":
            self.frlcor = (-self.frlxdis, self.frlydis)
        elif pos == "right":
            self.frlcor = (self.dist, 0)
        elif pos == "bottomright":
            self.frlcor = (-self.frlxdis, -self.frlydis)
        elif pos == "bottom":
            self.frlcor = (0, self.dist)
        elif pos == "bottomleft":
            self.frlcor = (self.frlxdis, -self.frlydis)
        elif pos == "left":
            self.frlcor = (-self.dist, 0)
        elif pos == "topleft":
            self.frlcor = (self.frlxdis, self.frlydis)
        else:
            print("WARNING! plugins.frl.__init__: FRL position argument '{}' not recognized; FRL position set to 'centre'.".format(pos))
            self.frlcor = (0, 0)

        if disptype in ["pygame","psychopy"]:
            self.disptype = disptype
        else:
            raise Exception("Error in plugins.frl.__init__: disptype '{}' not recognized".format(disptype))

        if self.disptype == "pygame":
            self.__class__ = PyGameFRL
        elif self.disptype == "psychopy":
            self.__class__ = PsychoPyFRL
            self.frl = Aperture(pygaze.expdisplay, self.size, \
                pos=pos2psychopos(self.frlcor), shape="circle", units="pix")


class PyGameFRL:

    """Gaze contingent FRL based on PyGame"""
    
    def get_pos(self, gazepos):
        
        """Returns FRL position tuple, based on gaze position; for internal
        use
        
        arguments
        gazepos    -- a (x,y) gaze position tuple
        
        returns
        frlpos    -- a (x,y) position tuple, indicating the FRL center
                   coordinate
        """

        return (gazepos[0]-self.frlcor[0], gazepos[1]-self.frlcor[1])


    def update(self, display, stimscreen, gazepos):

        """Updates display with FRL, showing part of the stimulus screen
        inside of a FRL and backgroundcolour everywhere else
        
        arguments
        display    -- a libscreen.Display object
        stimscreen    -- a libscreen.Screen object containing the stimuli
                   that are to be presented
        gazepos    -- current gaze position
        
        returns
        disptime    -- directly updates display and returns refresh time
                   (PsychoPy) or an estimate (PyGame)
        """

        # frl position
        frlpos = self.get_pos(gazepos)

        # reset display surface
        display.fill()
        
        # draw new FRL
        r = self.size/2
        # In pixels. updaterectheight (FRL actually consists of a stack of
        # rectangles, h is the height of an individual rectangle)
        h = 1
        # top side
        for y in range(0,r):
            # right end of rectangle
            y = r - y # reverse y
            x = (r**2-y**2)**0.5
            # rectangle coordinates
            updaterect = [frlpos[0]-x,frlpos[1]-h*y,2*x,h]
            # update screen part
            pygaze.expdisplay.set_clip(updaterect)
            pygaze.expdisplay.blit(stimscreen.screen,(0,0))
        # bottom side
        for y in range(0,r+1):
            # right end of rectangle
            x = (r**2-y**2)**0.5
            # rectangle coordinates
            updaterect = [frlpos[0]-x,frlpos[1]+h*y,2*x,h]
            # update screen part
            pygaze.expdisplay.set_clip(updaterect)
            pygaze.expdisplay.blit(stimscreen.screen,(0,0))

        # unset clip and update display
        pygaze.expdisplay.set_clip(None)
        disptime = display.show()
        
        return disptime


class PsychoPyFRL:

    """Gaze contingent FRL based on PsychoPy"""
    
    def get_pos(self, gazepos):
        
        """Returns FRL position tuple, based on gaze position; for internal
        use
        
        arguments
        gazepos    -- a (x,y) gaze position tuple
        
        returns
        frlpos    -- a (x,y) position tuple, indicating the FRL center
                   coordinate
        """

        return gazepos[0]-self.frlcor[0], gazepos[1]-self.frlcor[1]


    def update(self, display, stimscreen, gazepos):

        """Updates display with FRL, showing part of the stimulus screen
        inside of a FRL and backgroundcolour everywhere else
        
        arguments
        display    -- a libscreen.Display object
        stimscreen    -- a libscreen.Screen object containing the stimuli
                   that are to be presented
        gazepos    -- current gaze position (a (x,y) tuple)
        
        returns
        disptime    -- directly updates display and returns refresh time
                   (PsychoPy) or an estimate (PyGame)
        """

        # FRL position
        frlpos = pos2psychopos(self.get_pos(gazepos))

        # set FRL
        self.frl.setPos(frlpos)
        self.frl.enable()

        # draw stimuli
        display.fill(stimscreen)

        # update screen
        disptime = display.show()

        # unset FRL
        self.frl.disable()
        
        return disptime
